Science fiction has implanted all kinds of ideas in our minds. Some of them, ingenious and downright genius, were the seeds of cutting-edge technologies. Others, on the other hand, take advantage of the complex scientific vocabulary to entangle our thoughts and leave us confused, rambling about what they have just told us. The latter do not usually transcend fiction.

They do not pass from act to potency, they do not materialize in any way. They are far-fetched ideas that are more fanciful than achievable. For example, space elevators seem to be from the latter. Big cables hanging from a satellite that, like the fakirs, we could climb out of orbit. Now, what about teleportation?

One classic

As with many other questions, the answer in this case is “it depends”.”. It depends on what we mean by teleportation. If we talk about making an object disappear and reappear at a specific place in space as if we were copying it, this (in the absence of amazing new physics) seems completely unrealizable. In that sense, we can teleport particles. Or, better said, teleportation, since the idea is that he doesn’t pass through anything, but travels without going through the space between two points.

Quantum technologies have allowed us to harness quantum teleportation, but with absolutely minuscule elements. The number of subatomic particles that make up our bodies is like a jigsaw puzzle with an infinite number of pieces. If we want to destroy and reconstruct a human body, we would have to know them all and the amount of information (and the expected errors) would be too high to accomplish this. And, of course, one would also need to consider the philosophical detail that if we destroy and rebuild a person, however much their behavior and memories are the same… is it the same person? Did we kill someone? However, there may be another alternative.

black holes

Another classic of science fiction teleportation is wormholes, tunnels that bend space to travel through it as if you crumpled up a road map and drove a toy car through it. To understand how they should work, we must remember what a black hole is. To understand it in a simplified way, we must think of a black hole as a region of space, not as an object itself. The reason is that when we talk about it, we take for its parts areas of space where there is not much more than deformations in space-time itself. That’s why we talk about a region. Anyway, the important thing is that this area has an enormous density. Now is when things start to get weird.

A large mass concentrated in a small part of space. Although the situation is different, we can imagine it as lying on a trampoline. Possibly it yields a little, deforming the fabric, but if we stand up, concentrating our mass on a smaller surface, like our feet, the deformation will also increase, sinking even further into the bed.. If we forget that the trampoline is flat while spacetime has three spatial dimensions and one temporal dimension, we can get an idea of ​​how mass also deforms the spacetime it is in. The important thing, in any case, is to intuit that the geometry of spacetime can change when it interacts with very dense objects.


Well, if a black hole is capable of bending space-time, what would happen if it bends it so much that it ends up joining another point in space-time? As if it were a balloon in which we dip our finger until we reach the opposite side. Theoretically (and saving the multitude of details we are omitting in this explanation), a kind of conduit could form between these two regions of space-time, a tunnel that we call a “wormhole”. We never found one. We’re not even sure they exist, let alone stable, but we’ve seen them in science fiction. movies like interstellar they raise the possibility of crossing them to cover insurmountable distances through this type of shortcut.

Let’s think for a moment what that means. In the universe there is a speed limit above which nothing can accelerate: the speed of light in a vacuum. This means that, to cover very long distances, we will always be limited to this: around 300,000 km/s. However, if we could create a tunnel, we could cover the distance between two points in less time without going faster than light. In the same way that tunnels allow us to cross mountains in less time than if we had to go around them, even going at the same speed.

The idea doesn’t sound entirely bad, but there’s a catch. Or rather, several. The first is that, as we said, we don’t know if these wormholes are stable (if they exist at all). It is possible that they last very small fractions of time and, even if they are stable, that an object that passes through them ends up destabilizing them. The other problem is also not negligible. In principle, we could not use them at will, we would have to take advantage of those that were already there, as if we were navigating rivers, clearly faster than going inland, but there is no river that takes us from León to Seville. The alternative would be to build them, create wormholes where it suits us, as they did, once again, in interstellar. Now… how much energy would we need for something like this? Not only would we have to distort spacetime in an extreme way, which is already very energy intensive, but we would have to keep it that way as long as an object passes through it.

The problems

In theory, this last option could be possible, perhaps even energetically more profitable than destroying and rebuilding a human being particle by particle, but it is still a long way from any current technology. And not only does it lack the technology to generate them, but we don’t have the energy production capacity to cover such an expense. So while teleportation is not a fiction destined to last forever, there is no solution in sight for now. Who knows what the future may bring us. Technology doesn’t always move forward in a straight line, it accelerates every time we overcome a complication and, in those moments, it can deviate, exploring paths that we thought were impossible. Perhaps this is the future of teleportation, space-time origami.


  • When we talk about the inside of black holes, the word “singularity” usually comes up, it describes a place where we can’t calculate exactly what happens because our formulas fail, throw infinite values. In non-rotating black holes, the singularities are points, in those that rotate they would be toroidal (doughnut-shaped) and could be several. However, as we see, these are uncertainties, not real objects to collide with. We need a better mathematical explanation of how black holes behave to clarify many of the seeming paradoxes that currently haunt us. That’s why there are so many highly speculative hypotheses about connections between black holes, time travel and other stories that are, by the hour, just science fiction.


  • Accretion of winds from RGB stars may reveal supermassive black hole in Leo I The Astrophysical Journal Letters 10.3847/2041-8213/ac9b21